Grinding mill



Sept. 6, 1932 w. LETZ 1,875, 743 GRINDING MILL 4 Filed Feb, 3, 1935 Fij.-]. 2 26 15 IN VEN TOR.

% ATTORNEYS.

in the eveht a stray holt 01 nut, 01' any othev Patented Sept. 6, 1932 NI 'D 3mm ;PA NTT{ WILLIAM n. LETZ, 01 cnoWn POIN-T, INDIAN, Assmnon wo TUBE LETZMANFAG'IR- ING comrmxnr, A conromnon OF INDIANA 1 V'GVBINDING MILL The-present invention is directed genorally to improvemehts in grinding mi-ll coms'tructiom but mofe particulazly 130 a novel and improved construotion which encases th'e grinding plates or burrs so that in the' eVent of the aocidental breaking of the grinding plates the broken parts thereof are -retained Wlthiir1 the casing so as to prevent breakage of othe1: parts of thegrinding mill.

' Oma of the o]oj6cts of'the pre'se'rit invention is to pfovicle a novel und. improved form of gringing plate 01 burr protector which substantiailly encases both the revolving grinding plate and stationary grincling plate',so that foreign obstacle is accidentally thrown between the grincling member's, and Tesul ts in thebteaking 0f the'- grinding'- plates into' 011e 01 more pieces, the casing thu's provided pre} venlts the Pieces 0f broken grinding plate from leaving their position', obviously profventing the fiying pieces of the grincling@late to causedamage to'-the othr parts of the mill. l

A still further object ofthe invention is to provide a novel and improved construction of mill, so that in the elvent of the accidental breaking of the grincling plates ofa mill bj riaason of'foreig'n substanbes getting between the grin clingflates,the dmmage caused thereby is reclced to the merer'e7'alacemeflt 'of the pltes wit-hout cla'mage t0 oth er parts.

These and other objectsare acconiplished by providing a construction and arrangemnt 0f the various arts in the manner hereinafter describecl, ancl particularly pointed out in the appenclecl claims.

Referring to the clrawing, 1 Fig. 1 is a longitudinal cross sectional vie'w ofa fragrrientary portion of a converitional form of; grinding mill showing my'impr0veawzly, und also sihowin 1tly impro ved =gliilding plate protector mounted between fthe -platsholder on the grindingplate.

ofthe s'teel disks Which encases gl e plaiqe or burr; U l v v Heretofore, Whenover;a holt, a la-1"ge woden screw, 01" a ny other hard obstnlctionakzciclent'ally found its wy between the; gri1iding plates 01 burrs 0f a grinding 1mill, "oho results were that one or both of the grinding plates broke and the flying pieces of the giindin g plate caused the breaikagej of other Parts 035 tho grinclihg mill,such as the grinding platte cove'rsor the"castii1g Which -Surrounds the grincling plates, th'e'reby enta iling consiclerable delay and eztp'ense to the' operatorof the ma ihi'ne. 1

It is,therefote, the primaty Object of th present invention t o alleviate this diffid1ilty and redce the, damage c'ausedby th'e bregak-v ing of the' gri1'1ding plates 01 bu'rrs t0 -a minimum. T 1

In the drawing I have sh0wn the presnt constrction comprising ab rela'tivelythin steel disk occupying bu t a little space between the plate holder 2u1d grinding plate, thereby. provicling avery stron'g anl practically indestru'ctible shield 01 casing for retaining the grinding plates therebetween, so that in the event of theaccidei1tal bfeg'xking of the grinding plates the'flyingpiedes of the same Will be Prevented from cusin(g frther clainge.

It Will of coursei be umlerstood that the'grinding platte holde? may be constructed with a recesstherein so as 130 form in effect a casirig surrounding each grlnding plate.

In illustrating one embodiment 0f my in'- .venfiion, I have shown the same incohnecti0n With acnventional formof grinding mill, Whic h comprises the usul supportlng frgune structure 10, which in turn is provided wich the usual concave 11, and the crushing and conveying screw 12 munted 011 the usual sha ft 13. Mounted forwardly of the conveying screw 12 and secured to the shaft 13 in the usual manner is an auger 14:. Secured to the frame structure in a manner Well understood in the art is a grinding frame casing 01 cover 15 which has secured thereto by means 0f bolts 16 a complemehtary member 01 c0ver 17. One endjof the. coveris provi ded With 2i suitable b0aring m ember 18 in Whi0h tl1e shaft 13 is journalled therein. C onneeted tofohe lower side of the cover members 15 and 17 is a dischargespout 19 *through Which tl1e" ground grain is discharged int0 suitable re-* ceptacles in a. manner well underst0od in the art.

The construction thus far des0ribed is the;

conventional form 0f griiiding mill, and a 1i1ore detailed descripti0n of thesame is unnecessary.

The inventionin the present instanee i's directed to a novel and improved construction in Which the station'ary and r0tary grinding plates and burrs are substantially encased between two steel jdisks so thatin thee'vent 0f thej brea'kage 0f either 011e of the grinkliilg plateis or burrs, the broken parts thereof Will be prevented fr0n'1be00mingdisl0dged frorn their position'and thereby prevent the breale age of 0ther parts 0fthe mill. These steel disk prot0ctors generally indicated by theireferenge charaeter 20 'are preferably made 0:E relatiyely thin sheet ste'el, and are secured to the i rotary and s tationeiry burr holdeis 21 and22 respectively by mearis of the usual bolts 23 and 24' which 'secure the grinding plates 01 burrs 130 the plate holders. These steel disks are, provided' with relatively' large ee;ntr.al

bores 25, and have their peripheries as shown Qat.26bent als substantially right angles With respect t0 the plane of the clisk portions there- 0fso as to form iriefl'ect arecess f0r therefcePtion f therotary and stationary grin ding plates 27 and 28 respectively. The adj ace11t edges of each 011 the steel disks 20 es shown' at 29 approzg0h in close proximity t0 the c0ntacting 0r grinding surfaces 0f ea eh oftlie grinding plates 0r burrs 27"2111d285 soas to Confine 01 substantially encasethe maj 0r portiofn ofthetw0 g1inding plates, so thatin the event Ofthebreakage 0f either of these places by sonne hard f0reign substance, the

1 pie ces 0f the burrsrresultihg from such a bre akage cannofi be disl0dged from their posit1on so as 130 cause further breakage of the 0511er parts 01 the mill. The rotary plate holder 21 is provided .W ith oppositely disp0s'ed lugs 30 which in turn have fheir outer j endsybent forwardly and als rightangles t0' the mein Portion es shown 'at 31, so as t0, en-

gage the outer fiange cf the disk 20. Itis of c0urse understood that the plate h0lder2l seci1red t'0 the shazft 18 by the usual phi 32.

From the above description it will readily be seen that in the event 0f a hard foreign substance being accidentally received between the grinding plates which results in the breakage 0f ehe plates, that the broken pieces resulting from said breakage Will not be permitted #0 be discharged from within the 0a sing 'formed by the tw0 steel .disks, and thereby prevent further breakage 0f the other arts.

Whilein the ab0ve specification I have describedone embodiment' Wl1il0ll my invention may assume in practice, it Will of cofuirse be understged that the same is cap able of modi- -0I-1 saidframe, a plate holder secured 130 sati d shaft, a grinding plate securedto sziid plate holder, a, relatively s tationary grinding plate secured t0 said frame and cooperatingwith said first-mentioned plate, and disks secured adjacerit said plat0s having a, peripheral fiange formed thereon forming a recess for the reception of each of said grinding plates -for substantially en casing both 0f said plates whereby the broken parts-ofsaid grinding 1 plates 'resulting-from the accidental-breakii1g of said plates are prevented from being diScharged fromm between said disks 2..The combinatiou with a grindingmill having a 'frame, of a rotary shaft mounted 0n saidframe, a plate holder secured to said s haft a grinding plata secured to said plate holder; Sa disk': secured between said plate holder and said grinding plate, and e, peripheral flange f0rmed 011 said disks for retaining therein thebroken parts of said plate resulting from the accidental breaking of said grinding plate. j

' S. The combination with agrinding mill havi1ig a frame,ef a rotary shaft mounted 011 seid frame, a plate holder securedto seid sh'aft, agririding plate sezcured to seid plate holder, a seeond plate holder secured 130 said frame, a second grinding plate seeured 120 said second plat-e holderand cooperating; with said first named grinding plate, and steel disks mounted betpween eaeh of said plate holders and said grinding plates for substan'- tially ericasing both ofsaid plates whereby the broken' parts 015 said grinding plates resulting fr0m the accidental breaking thereof are prevented from being tween seid disks.

0f a fremether'efor, arotary shaft mounted 0n seid frune, a plate holdersecured to sai d shaft, a disk having a peripheral flange secure clft-o said plate..holder foiencasing a 'g1inding plate attzehedtherefio, a relatilvely dischar'ged from bey 4. The. combination with a gril'idingmill stationary plate holder secured t0 said frame, anrl a disk having a peripheral flange seca1red to said stationary p1ate holder for encas ing a relatively stationary grinding platte secured thereto whiareby the grinding plates are substantially encased so that the broken part'S thereof resulting from the accidental breaking of sflid p1aces are prevented from being displaced from said casing.

In testimony whereof I have signed. my name to this specification, 011 this 16th day of January A. D. 1930.

WILLIAM H. LETZ. 

